A hematoma is a localized collection of extravasated blood (e.g., blood from a ruptured blood vessel or the like), usually clotted, in an organ, space, or tissue; bruises and black eyes are familiar forms that are seldom serious. Hematomas can occur almost anywhere on the body including inside the skull, and are almost always present with a fracture; in minor injuries the blood is absorbed unless infection develops.
Hematomas inside the skull are particularly serious, because they can produce local pressure on the brain. The two most common kinds of these are epidural (outside the brain and its fibrous covering, the dura, but under the skull) and subdural (between the brain and its dura). Other types of hematomas occurring inside the skull include intracerebral (in the brain tissue) and subarachnoid (around the surfaces of the brain, between the dura and arachnoid membranes). Such hematomas can result from a number of causes such as head injury or head trauma as well as due to bleeding disorders or an aneurysm.
Subdural hematomas are usually the result of serious head injury. When a subdural hematoma occurs this way, it is typically called an acute subdural hematoma. Acute subdural hematomas are among the deadliest of head injuries as the bleeding fills the brain area very rapidly, thereby compressing brain tissue, which can lead to brain injury. Also, risk for a subdural hematoma can be increased by one of more of the following; taking anticoagulation medication (e.g., blood thinners including aspirin), long term alcohol abuse, recurrent falls, and repeated head injury. Risk also is increased for the very young and the very old.
Subdural hematomas also can occur from a minor head injury, especially when the injured is elderly. Such hematomas can go unnoticed for a long period of time (e.g., many days to weeks) and are often called a chronic subdural hematoma. With any subdural hematoma, tiny veins between the surface of the brain and its dura stretch and tear, allowing blood to collect. In the elderly, such veins are often stretched because of brain atrophy or shrinkage and thus are more easily injured.
Because of the negative consequences associated with hematomas inside the head or skull, it is necessary to be able to identify and locate such hematomas inside the skull, such that appropriate medical and surgical procedures (e.g., evacuation of the hematoma) can be timely undertaken so as to reduce the chances for mortality and/or worsened outcome in survivors. Such timely undertakening is on the order of about 4 hours from occurrence of the injury and the evacuation of the hematoma.
CT scanning is one imaging technique that can be used to identify and locate traumatic intracranial hematomas. However, all medical facilities (e.g., trauma centers) do not necessarily have immediate CT scanning capability on a 24/7 basis and thus it may not be possible in such cases for a CT scan to be performed so that an identified hematoma can be evacuated within the desired time frame. Also, in emergencies involving head trauma in underdeveloped areas of the world, areas in the US which have limited access to trauma centers having 24/7 CT scanning capability or in areas of the US or the world (e.g., a battlefield) having travel time issues from the site of the injury to the treatment facility; timely identification of patients that require surgery for dealing with the hematoma can be more difficult. Thus, in such settings where a CT scan cannot be performed with the desired time frame, the primary method for identification of patients with hematomas is by means of a neurological exam.
A neurological exam, however, is a poor substitute for a CT scan because no single physical sign can reliably indicate the presence of a hematoma. Focal neurological findings are found in only a fraction of patients with surgical hematomas. Coma has been reported to occur without the occurrence of a surgical hematoma in a large percentage of patients with sever head injury. Although patients with an intracranial hematoma will exhibit increased intracranial pressure (ICP), edema of the optic disk (papilledema), associated with ICP, is uncommon after head injury.
There is found in U.S. Pat. No. 5,954,053, systems that utilize differential measurement of radiation that has migrated through migration paths between two source-detector pairs placed on the head in a manner that each path is localized in a portion of one hemisphere of the brain. Various spectrophotometer systems are also shown for in vivo examination of tissue of a human by measuring changes in electromagnetic radiation scattered and absorbed in a migration path in the tissue. Generally, the spectrophotometer systems comprise a light source for introducing the radiation into the tissue, a detector for detecting radiation that has migrated in the tissue, a processor for processing signals of the detected radiation to create processed data, and a system for determining physiological or pathophysiological changes in the tissue of interest such as bleeding or tumor.
There is found in U.S. Pat. No. 7,139,603, methods and systems that examine tissue positioned between input ports and a detection port. At lease one light source of a visible or infrared wavelength is provided that introduces electromagnetic radiation into the subject. The detection port is optically coupled to a detector that is connected to a detector circuit. Radiation intensities are selected for introduction at the input ports to define a null plane in the tissue. The detection port is positioned relative to the null plane. Radiation is introduced into the subject at the first input port and the radiation that migrates through the tissue is detected. The detector circuit stores a first detector signal corresponding to the first detected radiation. Radiation is introduced at the second input port and is detected. The first detector signal is subtracted from a second detector signal corresponding to the second detected radiation to obtain processed data.
There is found in U.S. Pat. No. 7,610,082, an optical examination technique that employs an optical system for in vivo non-invasive transcranial examination of brain tissue of a subject. The optical system includes an optical module arranged for placement on the exterior of the head, a controller and a processor. The optical module includes an array of optical input ports and optical detection ports located in a selected geometrical pattern to provide a multiplicity of photon migration paths inside the biological tissue. Each optical input port is constructed to introduce into the examined tissue visible or infrared light emitted from a light source. Each optical detection port is constructed to provide light from the tissue to a light detector. The controller is constructed and arranged to activate one or several light sources and light detectors so that the light detector detects light that has migrated over at least one of the photon migration paths. The processor receives signals corresponding to the detected light and forms at least two data sets, a first of said data sets representing blood volume in the examined tissue region and a second of said data sets representing blood oxygenation of the examined tissue. The processor is arranged to correlate the first and second data sets to detect abnormal tissue in the examined tissue.
There is found in International Publication No. WO 2006/121833, a system and method for determining a brain hematoma including a handheld device for emitting and detecting radiation with a removable light guide assembly. The method for determining a brain hematoma condition includes determining optical density of various regions of the brain using near infrared spectroscopy.
In the above identified International Publication, the described device is positioned at a specific location of the head and data is acquired using the device. After acquiring data at this location, the device is re-located to another location of the head and another set of data is acquired at the new location. This relocation of the device and acquiring a set of data is repeated until the device has been placed at all possible or desired locations of the head.
It thus continues to be desirable to provide methods, devices, apparatuses for detecting hematomas in tissues of a patient. More particularly it continues to be desirable to provide such methods, devices and apparatuses for detecting and identifying a hematoma, yet more particularly the type of hematoma inside the head of the patient. It also would be desirable to provide such methods, device and apparatuses that allow a clinician. medical personnel, emergency medical technician, medic/coreman or the like to detect such a hematoma with out requiring the use of sophisticated imaging systems or techniques such as CAT scan or MRI systems and in a wide range of settings including hospital ER settings and usage in the battlefield, rural areas or in less developed areas of the world. Such devices preferably would be simple in construction and less costly than prior art devices and such methods would not require highly skilled users to utilize the device.